function checkPlatformContact(player, playerBody, platform){
    if(player.x >= platform.x - level.gridSize / 2
       && player.x <= platform.x + level.gridSize / 2
       && playerBody.linearVelocity.y >= 0.0000
       && player.y - playerBody.height / 2 <= platform.y - platform.height / 2){
           return true;
       }
}
